Experimental and theoretical x-ray magnetic-circular-dichroism study of the magnetic properties of Co50Pt50 thin films

An experimental and theoretical investigation of the structural and micromagnetic properties of the Co,,Pt,, ordered alloy is presented. The Co-3d and Pt-Sd orbital and spin magnetic moments and their anisotropies are determined by means of angle-dependent x-ray magnetic-circular-dichroism (XMCD) measurements. Our calculated spin magnetic moments of both Co and Pt are in good agreement with our experimental results, while the orbital magnetic moments are underestimated. The reduction of the 3d and 5d orbital magnetic moments, observed when the spin magnetic moment is forced out of the easy axis of magnetization, is reproduced by the theory. The calculated XMCD reproduces semiquantitatively the experimental spectra and underestimates the so-called branching ratio. The computed magnetocrystalline anisotropy is of the same order of magnitude as the experimental one with the correct sign.